In 1976, Crown became the first and only United States company to obtain a license from Heinz Schumacher for the Desolventizer-Toaster-Dryer-Cooler (DTDC). Crown has continually modified and improved the design, offering the most efficient DTDC built. Today, it is known as the Crown/Schumacher design.

Desolventizer-Toaster Operation

After all the oil has been removed from the oilseed flakes or cake, they leave the Crown Extractor with approximately 30% solvent (hexane) content. The Crown/Schumacher Desolventizer-Toaster (DT) is the newest innovation in removing the hexane from the flakes and completing the toasting operation.

Dryer-Cooler Operation

From the DT, the flakes are either conveyed to a Dryer-Cooler (DC) or, in the case of a Crown DTDC, they pass through the rotary valve, directly into the drying section of the DC. The drying and cooling are accomplished by blowing heated air in the drying section (dryer trays) and using ambient air to cool the meal in the cooling section (cooling tray).

More stable meal temperatures in all lower trays allow a greater degree of safety. A drop in meal temperature in the top tray due to operation errors can also be recovered more easily in the second or succeeding trays

The predesolventizing by the steam-heated trays reduces the amount of sparge steam required and also reduces the meal moisture proportionally, thereby reducing the steam usage in the meal dryer